﻿<p>The standard beam,
<em>IfcBeamStandardCase</em>, defines a beam with certain constraints
for the provision of material usage, parameters and with certain
constraints for the geometric representation. The
<em>IfcBeamStandardCase</em> handles all cases of beams, that:</p>
<ul>
<li>have a reference to the <em>IfcMaterialProfileSetUsage</em>
defining the material profile association of the beam with the
cardinal point of its insertion relative to the local
placement.</li>
<li>are consistent in using the correct cardinal point offset of
the profile as compared to the 'Axis' and 'Body' shape
representation</li>
<li>are based on a sweep of a planar profile, or set of profiles,
as defined by the <em>IfcMaterialProfileSet</em></li>
<li>have an 'Axis' shape representation with constraints provided
below in the geometry use definition</li>
<li>have a 'Body' shape representation with constraints provided
below in the geometry use definition
<ul>
<li>are extruded perpendicular to the profile definition plane</li>
<li>have a start profile, or set of profiles, that is swept</li>
<li>the sweeping operation can be linear extrusion, circular
rotation, or a sweep along a directrix</li>
<li>the start profile, or set of profiles can be swept unchanged,
or might be changed uniformly by a taper definition</li>
</ul>
</li>
<li style="list-style-type:none">
<blockquote class="note">NOTE&nbsp; View definitions and implementer
agreements may further constrain the applicable geometry types,
e.g. by excluding tapering from an <em>IfcBeamStandardCase</em>
implementation.</blockquote>
</li>
</ul>
<blockquote class="history">HISTORY&nbsp; New entity in IFC4.</blockquote>


<p><b><em>Geometric Representations</em></b></p>
<p>The geometric representation of <em>IfcBeamStandardCase</em> is
defined using the following multiple shape representations for its
definition:</p>
<ul>
<li><u>Axis</u>: A three dimensional open curve (subtype of
<em>IfcBoundedCurve</em>) defining the axis for the standard beam.
The cardinal point is determined by the beam axis.</li>
<li><u>Body</u>: A Swept Solid Representation or a CSG clipping
representation defining the 3D shape of the standard beam.</li>
</ul>
<blockquote class="note">NOTE&nbsp; It is invalid to exchange a 'SurfaceModel',
'Brep', or 'MappedRepresentation' representation for the 'Body'
shape representation of an
<em>IfcBeamStandardCase</em>.</blockquote>

